Screw propeller



May 12, 194-2. PETERSON 2,283,088

SCREW PROPELLER I FiledApriLZ 1941 Inventor dusfwv -732 irsaw Attorney Patented May 12, 1942 UNITED STATES T 1;

orrics 1 Claim.

This invention relates to screw propellers for use as traction upon boats; and an object of the invention is to improve generally upon such screw propellers as are now generally known and in use.

More particularly an object of the invention is to provide a screw propeller of such construction and arrangement as will permit the cutting of the propeller through the water with a minimum of resistance, yet at the same time delivering a pull far greater than the conventional type of propeller now in use.

A further object of the invention is to provide a screw propeller which will accomplish the above objects with minimum of effort.

The invention together with its objects and ad vantages will be-best understood from a study of the following description taken in connectionv with the accompanying drawing wherein Figure 1 is an elevational view of a propeller embodying the features of the present invention.

Figure 2 is a longitudinal sectional view thereof.

Figure 3 is an end view of the propeller from the free terminal end of the propeller shaft.

Referring more in detail to the drawing it will be seen that in the preferred embodiment thereof the propeller embodies an integral shaft 5 which at one end is adapted to be connected with the prime mover to be driven thereby and at the opposite end is reduced and tapered, as at 6, to further reduce friction and resistance.

Integral with the shaft 5 are, in the present instance, two spiral or screw blades 1 and 8. The propeller may have any number of blades but for purposes of illustration but two blades are shown.

As clearly shown, the blades are interwound spiral formations spaced diametrically opposite on the shaft 5 at the points 9 and H] where the blades merge or become integral with the shaft.

In the illustration shown each blade embodies substantially six convolutes, with the development of each blade being founded on the lines forming the junction between each blade and the shaft 5, and, starting from zero at opposite ends of the blade, each blade builds up to full height 5 in the first turn, remaining or retaining this full height from the second turn and then reduces from full height to zero in the third turn; each blade being substantially squared to the center of the shaft at any given point.

10 By reason of such construction and formation the propeller will cut through the water with a minimum of resistance; will develop maximum pull with minimum elfort, and its adoption and use on boats and various kinds of water crafts will, in actual practice, be found to materially promote marine transportation.

The invention together with its many advantages will be understood from the foregoing without further detailed description.

Also while I have herein illustrated and de- Having thus described the invention, what is claimed as new is:

A propeller comprising a shaft, a blade assembly including a pair of intercoiled spiral blades integral with the shaft and coiled oppositely from opposite ends of the assembly, respectively,

said blades at their juncture with said shaft extending along the same in diametrically opposite relation, said blades each including three coils, and said blades from one end of the assembly,

respectively, gradually increasing in diameter from the shaft to a maximum diameter in the first coil and having the second coil of the same diameter and the third coil gradually decreasing in diameter to the shaft, said blades being per- 40 pendicular to the axis of the shaft throughout the coils thereof.

- GUSTAV PETERSON. 

